<template>
  <h2>{{name}}--{{age}} -- {{num}}</h2>
  <button @click="add">+1</button>
</template>

<script>
export default {
  name: 'App',
  setup(){
    let name = 'su'
    let age = 21;
    let num = 1;
    function add(){
      alert(`${name},${age},${num}`)
    }
    return {
      name,
      age,
      num,
      add
    }
  }
}
</script>

<style>
</style>
